1. Field of the Invention
The present invention relates generally to apparatus for depositing a clear sorbitol sweetened hard candy, and more particularly pertains to a novel machine for depositing sorbitol sweetened clear hard candies on a continuous basis in a high volume commercial operation. The present invention is related to U.S. Pat. No 4,452,825, commonly assigned herewith, which discloses and claims a basic process pursuant to which the apparatus of the present invention is operated.
2. Discussion of the Prior Art
Over the years, there has been a demand in the confectionery industry for various reasons to produce a sugarless hard candy confection resembling ordinary hard candy in appearance and organoleptic qualities such as smoothness, non-tackiness, etc. Attempts have been made, for example, to replace sucrose, corn syrup, flavoring, and coloring with combinations of sorbitol, mannitol, and other materials including coloring and flavor.
While sorbitol is particularly suitable as a candy ingredient because of its close resemblance to sugar in sweetness and nutritive values, hard candy confections which include sorbitol are extremely difficult to prepare because of the inherent tendency of the candy pieces to remain soft and tacky instead of solidifying into hard candy as desired. At one time, hard candy made from sorbitol solution, crystalline sorbitol and crystalline mannitol usually included a gum, such as larch gum, acacia or tragacanth, in order to promote the "setting-up" or solidification of the confection. Since the inclusion of a gum necessitates relatively low cooking temperatures and a relatively high moisture content in the solution from which the confection is prepared in order to keep the gum suspended, the crystallization time for the confection is extremely long, frequently requiring as much as several days processing time. Moreover, when sorbitol-sweetened hard candy confections prepared with gum crystallize, clarity is destroyed because of the presence of the colloidally dispersed gum and by the surface crystallization of the sorbitol and mannitol.
Attempts to overcome some of the problems associated with the making of sorbitol-sweetened hard candy include processes such as that described in U.S. Pat. No. 3,438,787 to DuRoss in which an aqueous solution, containing sorbitol and not more than about one-fourth part by weight of mannitol per unit weight of sorbitol, is heated to reduce the moisture content to not more than 0.5% by weight of the solution before cooking to a temperature within the range of from 160.degree. F. to 200.degree. F. and seeding with no less than 0.5% by weight finely ground crystalline sorbitol, mannitol and/or carbohydrates to form a sugar-free hard candy after solidification in a controlled environment.
Another process is described in U.S. Pat. No. 3,371,626 to Hachtman wherein an aqueous solution of sorbitol is heated to a temperature above the melting point of sorbitol, sufficiently high to evaporate the water, and is then deposited into thin-walled cavities of a plastic mold while maintaining the temperature above the setting temperature but below the temperature at which the plastic mold cavity walls will heat-deform. This process was intended primarily to eliminate the need for starch molding which is a messy, dusty operation resulting in a cloudy starch coated product. Moreover, the plastic molds as taught herein are difficult to demold, crack easily and are insulative (causing increased set times).
Even though both of the processes described hereinabove reduce the time usually required for a confectionery aqueous sorbitol solution to set or solidify sufficiently to further process the hard candy units, such improved set times are still far in excess of a solidifying time which is appropriate for a high volume production of sorbitol-sweetened hard candy units. The DuRoss process takes at least an hour to yield a hard candy product, while the Hachtman method requires eight hours. Another method described in U.K. Pat. No. 1,403,696 to ICI includes melting sorbitol and mannitol crystals using only an amount of water sufficient to effect solution of the crystals. According to this disclosure a set time of fifteen minutes may be attained if the temperature of the melt is 140.degree. F. when placed in the molds. However, at a temperature of only 140.degree. F., the viscosity of the melt would be predictably so high as to effectively preclude processing on a continuous basis.
Other disclosures such as U.S. Pat. No. 3,738,845 to Liebrand and U.S. Pat. No. 4,241,092 to Halik, et al. show variations in cooking and processing in order to achieve different product results.
Candy depositing machines similar in some respects to those of the present invention are commercially available from Baker Perkins Holdings Limited, and U.S. Pat. No. 4,229,484 illustrates some details thereof of a typical machine. These commercially available depositing machines are constructed and designed to deposit many standard confectionery solutions in a very satisfactory manner. However, these machines are not suitable for depositing an aqueous sorbitol solution having therein a crystalline seeding material, as the commercially available machines are not capable of maintaining the solution within a relatively narrow temperature range required by the solution. The hoppers in these machines are frequently provided with a heating jacket therearound through which a heating medium is circulated. However, the depositing base of the machine is not provided with separate heaters therein, and the individual depositing nozzles extend and project downwardly for some distance (e.g. several inches) beneath the base. The individual nozzles of these machines are thus cooled to a great extent by the ambient air therearound, which results in rather fast thickening (large increase in viscosity) of the aqueous sorbitol solution therein and consequential blocking of the nozzles by the highly viscous solution. Moreover, the aqueous sorbitol solution is not adequately heated within the hopper, resulting in a "skinning" thick layer caused by cooling of the solution by the ambient air which results in an unacceptable increase in viscosity. Thus, a crust of highly viscous material forms on the upper surface of the sorbitol solution, interfering with continuous high volume depositing operations by a machine of that nature. Also, the components of these machines, such as the nozzles, the pumping rods, the pumping sleeves associated therewith, and the ball valves therein are frequently fabricated from materials, such as brass or copper, which are not fully suitable for use in the practice of the present invention as they tarnish and corrode due to acidulants used in processing.